GA under reporting page views.

I have got a simple report on GA which reports on the page views. The page views matches the number of successful transactions which have so far matched. However over the last 2 /3 weeks we are seeing Analytics under report the number of page views although there has been no change to the underlying code.

Another interesting thing I noticed is the real time page views do increment, so if I do a real time report over the last 30 minutes it has got the right numbers but the overall page views for the day remains unaffected (i.e. does not increment).

I have also removed any filters that might impact results but still seen no improvements.

Anyone else who has seen the same issue? Any pointers to fix this issue?